Latching lever assembly for door holder-closer

ABSTRACT

An improved latching lever assembly for use in an electromechanical door holder-closer having a closer spring, a dashpot, and an electromagnet. The electromagnet actuates the lever assembly to latch the spring-dashpot combination to effect a desired door hold open position. The lever assembly comprises a lever, a fulcrum at one end of the lever, and an armature located generally at the other end of the lever and electromagnetically coupled to the electromagnet. A latching detent is located on the lever intermediate the fulcrum and armature to latch a camming roller to arrest the spring-dashpot combination when the electromagnet is energized. An armature-lever coupling spring resiliently couples the armature to the lever to enable the lever to pivot about its fulcrum during manual override of the door holder-closer without a corresponding movement of the armature relative the energized electromagnet, thereby eliminating armature release noises.

( 1 May 1, 1973 Primary Examiner-James T. McCall Assistant ExaminerPeter A. Aschenbrenner Attorney-Augustus G. Douvas [57] ABSTRACT An improved latching lever assembly for use in an electromechanical door holder-closer having a closer E. DHooge, Wood Dale, both of 111.; Frank D. Roberts, North Reading, Mass.

Franklin spring, a dashpot, and an electromagnet. The electromagnet actuates the lever assembly to latch the spring-dashpot combination to effect a desired door hold open position. The lever assembly comprises a lever, a fulcrum at one end of the lever, and an armature located generally at the other end of the lever and electromagnetically coupled to the electroma s 2 e 7 rm 9 n a H w r m m a a PM gnet. A

16/61 latching detent is located on the lever intermediate the W305i 16/20 fulcrum and armature to latch a camming roller to arrest the spring-dashpot combination when the elec- 144; 49/1 2, 31 tromagnet is energized. An armature-lever coupling spring resiliently couples the armature to the lever to enable the lever to pivot about its fulcrum during manual override of the door holder-closer without a corresponding movement of the armature relative the energized electromagnet, thereby eliminating arma- References Cited ture release noises United States atet 1 Craneetal.

[ LATCHING LEVER ASSEMBLY FOR DOOR HOLDER-CLOSER [75] Inventors: Burke J. Crane, Lombard; Richard [73] Assignee: Rixs [22] Filed:

[21] Appl. No.: 230,735

[52] U.S. Cl. [51] Int. [58] Field of Search..........................

UNITED STATES PATENTS .X mm 88 mm 22 2 mm S E N "n m mm." 0. m a a n a m A m m "a C m u H II n u a" L n m mm P .m u I P "m M m A m m mm a R am WOdUS O w mm S cm ywmsm T a 0.1 N P T 285 6 A NM 765 5 99 99999 ll wmwmwm an 11 I E 62624 R W 26044 O 00 ,59 F 85304 5 4 085 8 332 2 Patented May 1, 1973 3,729,771

3 Sheets-Sheet 1 Patented May 1, 1973 3 Sheets-Sheet 2 Patented May 1, 1973 3,729,771

3 Sheets-Sheet 5 r I 07 I A 56 LATCHING LEVER ASSEMBLY FOR DOOR HOLDER-CLOSER BACKGROUND OF THE INVENTION This invention is directed to improvements in lever latching assemblies for use in electromechanical door holder-closers of the general type shown in U.S. patent application Ser. No. 878,604, now U.S. Pat. No. 3,648,326, filed Nov. 21, 1969 by Joseph J. Gaysowski.

The pertinent class of door holder-closer is characterized by a spring-dashpot combination which effects a controlled door hold-open or closing in response to the operative condition of an electromagnetically controlled latching lever. In many instances, such door controls are employed in association with a fire or smoke detector, so that a door that is held open will be automatically closed as a safety measure in response to a detected fire. As an additional requirement, such door controls must also be capable of being manually overridden as desired to close manually an otherwise open door.

Whether the door is released manually or in response to an undesired condition, an electromagnetically engaged latch must be released. Since in the many recent door controls the principal. door holder-closer elements, (namely, a closer spring dashpot, electromagnet and latching lever assembly) are all contained within a relatively small housing, short latching torque arm designs are employed.

With short torque arms, large latching forces must be developed to effect a reliable door hold-open. Generally speaking, this force requirement is not compatible with positive door release when the electromagnet is deenergized in response to fire detection, for example. The latch usually has inherent binding friction forces, which through component wear, may intensify to a point that the controlled door will no longer reliably close. This situation cannot be tolerated in door controls which are employed in fire safety systems.

Moreover, excessive binding friction forces can also produce a situation in which manual override to close a door can only be effected through excessive and uncomfortable manual exertion.

Another undesirable feature of many prior art latches employed in electromagnetically controlled door holder-closers is the attendant noise when the armature is separated from the electromagnet. In an installation requiring frequent manual override, each time the door holder-closer is overriden the armature is forcibly snapped away from the electromagnet with a loud discomforting noise.

This noise also occurs in response to closing of the door in response to the detection of the products of combustion; but the frequency of such an occurrence is so small that the attendant noise is tolerable.

SUMMARY OF THE INVENTION Accordingly, a principal object of this invention is to provide a latching lever assembly for a door holdercloser which is reliable in both its hold latching function and its emergency release function.

Another principal object is to provide a latching lever assembly for an electromagnetic door holdercloser which is relatively noise free during manual override.

o latching lever detent is located between the lever fulcrum and the armature to engage a camming roller. The roller rotates responsively with the dashpot rotor of the holder-closer to effect a latch hold.

By changing the lever latching detent to the midpoint of the lever as hereafter described, a mechanical advantage is achieved providing a higher holding force at the latching point of the roller and the lever detent. This increased holding force eliminates the otherwise critical nature of the latching function occurring generally due to wear produced friction, as well as poor adherence to manufacturing tolerances. In particular,

the roller surfaces and journalling are less critical. The I roller can freeze (not turn) and the door holder-closer will nonetheless release.

The inclusion of an armature-lever coupling spring enables the lever to be cammed away during manual override without requiring or causing the armature to separate from the energized electromagnet. Accordingly, the frequent and intense noises which accompany manual override are eliminated.

DETAILED DESCRIPTION OF THE DRAWINGS In order that all of the structural features for attaining the objects of the invention may be readily understood, reference is herein made to the drawings, wherein:

FIG. 1 is a view showing a typical electromechanical door holder-closer which incorporates internally the latching lever assembly of this invention;

FIG. 2 is a plan view of the door holder-closer of FIG. 1 with the housing cover removed, showing in full or in section the principal components of the holdercloser, namely, the latching lever assembly, electromagnet, dashpot and closer spring;

FIG. 3 is a side elevation of the structure of FIG. 2 with the dashpot partially in section (see lines 3-3 of FIG. 2) to show the details of the dashpot and the dashpot rollers;

FIG. 4 is a partial view of the door holder-closer showing the latching lever assembly being manually overridden from a door hold-open position and with the electromagnet energized;

FIG. 5 is a partial view of the structure of FIG. 4 showing the latching lever assembly being released in response to the deenergization of the electromagnet;

FIG. 6 is an elevation view showing the latching lever assembly coupled to the holder-closer dashpot by a fulcrum pin;

FIG. 7 is a section view of the latching lever assembly taken along line 7-7 of FIG. 6;

FIG. 8 is an exploded view of the latching lever assembly;

FIG. 9 is a plan view of the armature lever coupling spring before tensioning;

FIG. 10 is a side elevation of the coupling spring before tensioning; and

FIG. 11 is a typical failsafe schematic circuit which shows the connection of the electromagnet of the door holder-closer for manual switch operation or alternative operation by condition detecting means.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIG. 1, an electromechanical door holder-closer l which may advantageously incorporate the latching lever assembly of this invention is shown typically applied to a flush door 2 which is supported by a plurality of butt hinges 3 (only one of which is shown) upon a conventional metal door frame 4.

In general, door holder-closer 1 includes a track within which a slide block (not shown) reciprocates. The left end of standard arm 6 is coupled to the slide block. The right end of arm 6 is coupled to the holdercloser dashpot 11 (FIG. 2). The dashpot forms a part of an electromechanical combination housed within cover 7 which includes a coil spring, link chain, the dashpot, and the electromagnetic lever assembly of this invention.

In the usual preferred installation of door holdercloser 1, cover 7 and its contained components are fixedly positioned on the header trim of door frame 4 and track 5 is fixedly positioned immediately below cover 7 adjacent the upper edge of flush door 2, as is shown in FIG. 1.

With the foregoing disposition of components and the particular latch-lever assembly and camming roller dispositions hereinafter described, the opening of door 2 to either an approximate 30 to 35 opening range or to an approximately 90 to 150 opening range will enable the latch-lever assembly hereinafter described to hold door 2 in an open position in response to the energization of an electromagnet. Generally speaking, this holding action is accomplished by translating the door movement into a corresponding movement of the dashpot rotor connected to the right end of arm 6 (FIG. 1) so that the rotor is latched by the lever assembly. With this latching operation the door is held open until manually overridden, or alternatively, the electromagnet is deenergized in response to the detection of an undesired condition.

In FIGS. 3 and 4, cover 7 has been removed so that the principal components of door holder-closer 1 may be seen. Support frame 8, which is enclosed within cover 7, houses the following principal components; namely, spring coil assembly 9, link chain 10, dashpot l l, electromagnet l2 and latching lever assembly 13.

Spring assembly 9 includes compression coil spring 14 which envelops a spring rod 15. The left end of spring rod 15 is threaded (FIG. 2) so that the adjacent end of spring 14 is held by spring retainer 16. Retainer 16 is adjustably mounted relative threaded rod 15 by washer l7 and spring tension adjusting nut 18.

The right end of spring 14 is supported on spring support plate 19 which has a retaining circular flange 20. Flange 20 receives the adjacent contacting spring 14 turn. Accordingly, spring 14 is positioned relative to rod 15 by spring retainer 16 and spring support plate 19 so that adjustment of nut 18 can vary the static compression force generated by spring 14.

Lateral movements of spring 14 relative to frame 8 are limited by front spring guide 21 and rear spring guide 22.

The right end of spring rod 15 (FIGS. 2 and 3) is coupled to link chain 10 by connecting pin 23. The right end of link chain 10 is coupled to dashpot 11 by connecting pin 24.

In view of the fact that the latching lever assembly 13 of this invention cooperates with dashpot 11, the details of the dashpot, particularly with reference to FIGS. 2 and 3, will now be described. In FIG. 2, a simplified horizontal section view of the dashpot is shown and in FIG. 3 a simplified vertical section view taken along lines 3-3 of FIG. 2 is shown.

In its principal aspects, dashpot 11 comprises a fixed stator 25 which is housed within cavity 26 defined by generally cylindrical rotor 27. Stator 25 is formed with a pair of stator vanes 28 and 29. The stator and its vanes remain fixed at all times relative supporting frame 8. Stator 25 is formed with a mounting flange 30 (FIG. 3) which is fixed to frame 8 by a plurality of screws 31.

Rotor 27 supports a pair of integral vanes 32 and 33 (FIG. 2) which rotate with the rotor. As is shown in FIG. 3, rotor 27 comprises a cylindrical section 34 to which annular flanges 35 and 36 are fixedly attached. The rotation of rotor 27 produces a corresponding rotation of annular flanges 35 and 36.

Connecting pin 24 extends between flanges 35 and 36 to anchor chain 10 responsively to rotor 27. Likewise, roller pins 37 and 38 extend between the flanges so that rollers 39 and 40 may rotate relative their associated pins and between the flanges. Rollers 39, 40 also move responsively with rotor 27 and flanges 35, 36.

The interior dashpot cavity 26 defined between rotor 27 and stator 25 contains a viscoelastic plastic solid. This material may preferably be either a natural or synthetic unvulcanized rubber or an elastomeric-like material known as bouncing putty. this damping medium is contained within cavity 26 by means of O- ring seal 41; damping adjusting screw 42 is manually movable within its threaded bore to exert a varying pressure upon the damping medium through port 43 (FIG. 3). Rotor stem 44 receives the lower end of rotor cylindrical section 34 so that elements 34, 44 rotate in unison. Consequently, the attachment of standard arm 6 to stem 44 produces related movement between arm 6 and the dashpot rotor elements. Rotor elements 34, 44, including flanges 35 and 36, are rotatably fixed relative frame 8 by bearing plates 45 and 46.

Stepped pin 47 serves as an alignment bearing for rotor 27 relative stator 25.

As is shown in FIG. 2, electromagnet l2 and lever assembly 13 are closely associated with dashpot 11. In particular, electromagnet 12 is supported on frame 8 by electromagnet support plate 70.

Referring now principally to FIGS. 2, 6, 7, 8, 9 and 10, the latching lever assembly of this invention will now be described. The principal elements of lever assembly 13 are lever 50, lever fulcrum shaft 51, lever as-, sembly biasing spring 52, armature-lever coupling spring 53, armature plate 54, screw-washer-nut 5S, and spring alignment cylinder 56.

Lever 50 is formed with a latch detent 57 whose main function is to engage rollers 39 and 40 to effect hold open. The lever is also formed with a yoke having legs 58 and 59 from which lugs 61 and 62 project to receive coupling spring 53.

As is shown in FIGS. 9 and 10, coupling spring 53 is a helical wound torsion spring formed into two divided and joined sections 63 and 64 having a central spring connector loop 65 and two end connector loops 66 and 67.

In FIGS. 9 and 10, coupling spring 53 is shown in its untensioned disposition. In FIGS. 2, 4, 5, 6, 7 and 8, spring 53 is shown in its tensioned position; that is, end connector loops 66 and 67 have been rotated clockwise (with reference being made to FIG. 10) so that loops 66 and 67 are adjacent central connector loop 65 as is shown in FIG. 8. This disposition of connector loops 65, 66 and 67 places spring sections 63 and 64 in torsional tension. Accordingly, when loop 65 is rigidly fixed to armature 54 by means of bolt and nut 55 (FIG. 7) and end connector loop 66 is fixed to lug 61 and end connector loop 67 is fixed to lug 62, coupling spring 53 develops a strong torsional force which tends to force armature plate 54 against lever 50 as is shown in FIGS. 2 and 7. However, it should be noted that as shown in FIG. 4, the resiliencyof spring 53 enables armature plate 54 to be separated from lever 50 in response to oppositely directed forces, as will be hereinafter outlined.

When door 2 is closed, as is shown in FIG. 1, and regardless of the energized or deenergized condition of electromagnet 12, lever assembly 13 assumes the position shown in FIG. 2. As is shown in this Figure and also FIG. 6, lever 50 is pivoted relative dashpot 11 by means of fulcrum pin 51. Fulcrum pin 51 also receives biasing spring 52 so that a force is exerted by this spring which normally urges the lever assembly to the position shown in FIG. 2; that is, a position in which armature 54 rests against electromagnet 12.

When electromagnet 12 is energized, armature 54 is magnetically attracted to the core of the electromagnet. However, as door 2 is opened, rotor 27 (FIGS. 4 and 5) is rotated counterclockwise moving therewith chain 10 and thus compressing closer spring 14. The counterclockwise motion of the rotor also causes rollers 40 and 39 in that sequence to pass under latching detent 57 thus elevating lever 50 as is shown in FIG. 4. Armature 54, however, is magnetically fixed against electromagnet 12 in response to the energization of this electromagnet.

As the rotor 27 is rotated counterclockwise a further slight angle from that shown in FIG. 4, roller 39 is held in engagement against latching surface 57a of latching detent 57. With this occurrence, lever 50 is lowered so that it assumes the relative position with respect to armature 54 shown in FIG. 2. Door 2 is thus held open by the engagement of either roller 39 or 40 and latching surface 57a.

In the event it is decided to manually override the hold-open latch of door holder-closer 1, the clockwise movement of rotor 27 causes roller 39 or 40 to elevate or cam away lever 50 so that the closer spring 14 can rotate rotor 27 thereby causing standard arm 6 to move within track 5 to close the door.

It is important to note that during this condition of manual override, armature 54 is retained against electromagnet 12 as is shown in FIG. 4 so that there is no loud noise developed. In other words, during manual override, armature 54 always maintains contact with electromagnet 12. The resiliency of coupling spring 53 enables lever 50 to move upwardly without a corresponding movement in armature 54.

In the event door 2 is held open in response to the engagement of either roller 39 or 40 with respect to latching surface 57a, and electromagnet 12 is deenergized due to the opening of a manual operate switch or the detection of an undesired condition, lever assembly 13 is released as shown in FIG. 5 and rollers 39 and 40 cam latching detent 57 upwardly. In view of the fact that electromagnet 12 is deenergized, a holding force is not applied to armature 54 and the armature maintains its contact position with respect to lever 50 as a result of the torsional forces applied to armature 54 and lever 50 by coupling spring 53.

In all situations in which electromagnet 12 is deenergized, lever latching assembly 13 produces a characteristic release noise which is undesirable. However, in the usual installation of a holder-closer of the type described, an emergency release rarely occurs; accordingly, such noise can be tolerated. Manual override, however, is a commonplace occurrence, and in this instance latching lever release noises can attain an intolerable frequency unless eliminated by appropriate latching lever designs.

The schematic circuit of FIG. 11 shows typical electrical circuit effecting the connection of electromagnet 12 to effect holding and closing of door 2 in a failsafe manner of operation. Additionally, the schematic circuitry incorporates a condition responsive detector and amplifier-unit which is failsafe in operation. In particular, if all of the components of the detector and amplifier unit 80 are properly operating, door 2 will remain held in an open position effected by the latching of either roller 39 or 40 against latching detent 57 in response to the manual closing of control switch 81. If, however, detector and amplifier unit 80 is not properly operating or, alternatively, this unit senses a condition such as flame or smoke, door 2 will be released from a hold open position effected either by roller 39 or 40 and closed in response to the closing force exerted by coil spring 14.

The detailed operation of thecircuitry of FIG. 11 is as follows. Assuming detector and amplifier unit 80 is in proper operating condition and that the detector (not shown) input applied to terminals 82 and 83 indicates an absence of a flame or smoke condition, door 2 will be held in the open position in response to the manual closing of switch 81; that is, the closing of switch 81 applies line voltage from terminals 84 and 85 to amplifier A of unit 80. The application of line voltage to amplifier A energizes amplifier output relay 86, thereby closing normally open contact 86a.

The closing of contact 86a applies line voltage to the coil of power relay 87. With this occurrence, normally open contact 870 is closed, thereby applying line voltage to fullwave bridge rectifier 88 to energize electromagnet 12 with a pulsating direct-current voltage. (The physical position of a module containing bridge 88 is shown in FIGS. 2, 3, 4 and 5).

The energization of electromagnet 12 causes magnetic armature 54 to resiliently hold lever 50 downwardly (FIG. 2) and into locking engagement with either roller 39 or roller 40 against latching detent 57.

Accordingly, lever 50 holds rotor 27 with sufficient force to overcome the otherwise closing force exerted by coil spring 14. Thus, so long as electromagnet 12 is energized, door 2 will be held in an open position.

in the event, however, (a) a slight manual closing force is applied to door 2, (b) switch 81 is opened, (c) unit 80 malfunctions, or (d) an undesired condition such as smoke or flame is detected at input terminals 82 or 83, lever detent 57 will be pivoted from engagement with roller 39 or 40, as the case may be, and spring 14 will close the door to the position shown in F l6. 1.

In the situation of case (a) above, the manual override closing force causes disposition of the lever assembly 13 components as shown in FIG. 4 during the point of operation at which roller 39, for example, is in camming engagement with latching detent 57.

In situations (b), (c) and (d) above, electromagnet 12 is deenergized thereby enabling the camming action of roller 39 or 40, as the case may be (see FIG. 5), to elevate lever 50 as well as armature 54, as is shown in this Figure.

It should be understood that the structure shown in the drawings is merely typical, and that modifications can be made without departing from the scope of the invention. For example, the number and disposition of rollers 39 and 40 may be altered.

What is claimed is:

1. In an electromechanical door holder-closer having a closer spring, a dashpot and an electromagnet actuating a latching lever assembly to latch the spring-dashpot combination to effect a desired door hold-open position, the improved latching lever assembly comprising a lever, a fulcrum located generally at one end of the lever, an armature located generally at the other end of the lever and electromagnetically coupled to the electromagnet, and a latching element coupled to the lever intermediate the fulcrum and armature to latch the spring-dashpot combination when the electromagnet is energized.

2. The combination of claim 1 in which a door standard arm is adapted to couple door movements responsively to the door holder-closer to effect a manual over- 3. The combination of claim 2 in which an armaturelever coupling spring resiliently couples the armature to the lever which enables the lever to pivot about its fulcrum during manual override of the door holdercloser without a corresponding movement of the armature relative the energized electromagnet' thereby eliminating armature release noises.

4. The combination of claim 3 in which the armature is electromagnetically fixed to the energized electromagnet during manual override with the adjacent end of the lever moving away from the armature to enable the latching element to release the spring-dashpot combination.

5. The combination of claim 4 in which the armature-lever coupling spring resiliently biases the armature to a normal position in direct contact with the adjacent end of the coupled lever.

6. The combination of claim 5 in which a lever assembly biasing spring normally urges the lever assembly about the lever fulcrum so the armature makes contact with the electromagnet irrespective of the energized condition of the electromagnet.

7. The combination of claim 6 in which the springdashpot combination drives a cam element into latching engagement with the latching element to effect a door hold when the electromagnet is energized and in which the cam element pivots both the lever and armature in unison when the electromagnet is deenergized.

8. The combination of claim 7 in which the dashpot includes an internal stator and an external rotor with the rotor moving responsively to various door open positions and in which the cam element is supported by the rotor to move responsively therewith.

9. The combination of claim 8 in which the cam element is a roller and the lever latching element is a projecting detent.

10. The combination of claim 9 in which the end of the lever adjacent the armature is formed into a yoke, and in which the armature-lever coupling spring is a helically wound torsion spring formed into two divided and joined sections having a central spring connector element and two end connector elements with the armature fixed to the central spring connector element and the yoke fixed to both end connector elements. 

1. In an electromechanical door holder-closer having a closer spring, a dashpot and an electromagnet actuating a latching lever assembly to latch the spring-dashpot combination to effect a desired door hold-open position, the improved latching lever assembly comprising a lever, a fulcrum located generally at one end of the lever, an armature located generally at the other end of the lever and electromagnetically coupled to the electromagnet, and a latching element coupled to the lever intermediate the fulcrum and armature to latch the spring-dashpot combination when the electromagnet is energized.
 2. The combination of claim 1 in which a door standard arm is adapted to couple door movements responsively to the door holder-closer to effect a manual override of the lever in its latching position by application of a releasing force to the latching element.
 3. The combination of claim 2 in which an armature-lever coupling spring resiliently couples the armature to the lever which enables the lever to pivot about its fulcrum during manual override of the door holder-closer without a corresponding movement of the armature relative the energized electromagnet thereby eliminating armature release noises.
 4. The combination of claim 3 in which the armature is electromagnetically fixed to the energized electromagnet during manual override with the adjacent end of the lever moving away from the armature to enable the latching element to release the spring-dashpot combination.
 5. The combination of claim 4 in which the armature-lever coupling spring resiliently biases the armature to a normal position in direct contact with the adjacent end of the coupled lever.
 6. The combination of claim 5 in which a lever assembly biasing spring normally urges the lever assembly about the lever fulcrum so the armature makes contact with the electromagnet irrespective of the energized condition of the electromagnet.
 7. The combination of claim 6 in which the spring-dashpot combination drives a cam element into latching engagement with the latching element to effect a door hold when the electromagnet is energized and in which the cam element pivots both the lever and armature in unison when the electromagnet is deenergized.
 8. The combination of claim 7 in which the dashpot includes an internal stator and an external rotor with the rotor moving responsively to various door open positions and in which the cam element is supported by the rotor to move responsively therewith.
 9. The combination of claim 8 in which the cam element is a roller and the lever latching element is a projecting detent.
 10. The combination of claim 9 in which the end of the lever adjacent the armature is formed into a yoke, and in which the armature-lever coupling spring is a helically wound torsion spring formed into two divided and joined sections having a central spring connector element and two end connector elements with the armature fixed to the central spring connector element and the yoke fixed to both end connector elements. 